Flex and grid mixins to allow for semantic class naming

[ulinaaron]

Tent CSS is designed to be unsemantic by nature. The framework is more or less made up by chaining together classes to create components. While this is fine for most developers some may wish to use the objects and components with their own class names instead.

To do this much of the flex and grid objects will have to be rewrote to employ mixins. From a CSS distribution point of view this should have no real effect. This will only effect developers that wish to roll their own CSS output using the SCSS source files.

[ulinaaron]

This issue is a candidate for an upcoming release, I will move forward with the development on this.